Field of the Invention
The invention relates to a spray head with a capillary tube for seating on an aerosol tank.
Description of Related Art
A known spray head is shown in WO 03/051522 A2 (Published U.S. patent application 2003150885) which has the peculiarity that spraying of the fluid takes place without a nozzle. The fluid is introduced under high pressure into a capillary tube with a very small diameter and routed to an exit end from which it is sprayed without a nozzle. What is important is that the use of a capillary tube for this form of spraying of a liquid leads to the liquid being able to be sprayed even with little solvent and thus “dry” in a subjective perception. This novel spraying of low-solvent liquid is called “LoFlo”. It is characteristic not only that the liquid which is being sprayed is sprayed with little solvent, but that the spraying can take place even with a comparatively low propellant gas portion. Volumes and volumetric ratios in the capillary system are discussed in published U.S. patent application 2003150885. Extensive examples for all possible types of liquids which can be sprayed with this system are also cited in this reference. Also, the capillary tube extends from the entry end to the exit end which corresponds to the conventional alignment of a capillary tube. Metal tubes, plastic tubes or glass tubes can be used as the capillary tube.
Spray heads for aerosol tanks have been known for decades in a host of embodiments, such as disclosed in European patent application 0 409 497 and U.S. Pat. Nos. 5,388,730 and 3,848,778. In conventional spray heads, there is a tube which does not act as a capillary tube for transport of the liquid which is to be sprayed in the spray head. On the end of this tube there is a spray nozzle which causes the type and manner of spraying of the liquid. The pressure builds up for spraying the liquid at the nozzle, retroactively therefore in the tube. The fluid-dynamic relationships here are of a completely different type from in a spray head with a capillary tube for nozzle-less spraying of the fluid as in the present invention.
In conventional spray heads, millions of which are used for aerosol tanks, it is certainly important that the exit direction of the fluid for spraying lies essentially at a right angle to the axial fluid exit direction which is defined by the conventional female or male fluid exit valve on the aerosol tank. This relates to handling. The operator holds the fluid container (can) of the aerosol tank encompassed with three fingers and the thumb and presses with the index finger from overhead on the spray head in order to actuate the fluid exit valve of the aerosol tank. It is usually a normal seat valve or stem valve which has likewise been known for decades in a host of versions. Pressing down the spray head by finger pressure from overhead to open the fluid exit valve makes axial fluid emergence impossible and imposes fluid emergence which is directly essentially at a right angle thereto.
In the known conventional spray heads, aerosol tanks with conventional fluid exit valves are used. Conventional fluid exit valves for aerosol tanks have a valve body which is spring-loaded, to the top and which can be pressed down into the open position against the preliminary tension by the valve spring. This takes place for a female fluid exit valve by the valve tappet of the spray head, which tappet enters the receiving mount on the top end of the valve support. In a male fluid exit valve, a valve tappet which projects up is part of the valve body. The spray head has a corresponding receiver for this valve tappet. Pressing down the valve tappet opens the fluid exit valve.
A spray head is known for an aerosol tank with an atypical fluid exit valve as shown in U.S. Pat. No. 2,592,808. In this design, the fluid exit valve is part of the spray head. This spray head itself has an immersion tube which extends down into the fluid container and in which a capillary tube runs far into the fluid container. The capillary tube itself, together with a slip-in guide, constitutes the fluid exit valve. In the spray head, the capillary tube runs from the entry end to the exit end in an arc of roughly 90°, the course of the arc being ensured by interfitting outside and inside guides. This construction is not altogether suited for aerosol tanks with conventional fluid exit valves.